xref: /linux/drivers/base/platform.c (revision a5c4300389bb33ade2515c082709217f0614cf15)
1 /*
2  * platform.c - platform 'pseudo' bus for legacy devices
3  *
4  * Copyright (c) 2002-3 Patrick Mochel
5  * Copyright (c) 2002-3 Open Source Development Labs
6  *
7  * This file is released under the GPLv2
8  *
9  * Please see Documentation/driver-model/platform.txt for more
10  * information.
11  */
12 
13 #include <linux/string.h>
14 #include <linux/platform_device.h>
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/bootmem.h>
19 #include <linux/err.h>
20 #include <linux/slab.h>
21 #include <linux/pm_runtime.h>
22 
23 #include "base.h"
24 
25 #define to_platform_driver(drv)	(container_of((drv), struct platform_driver, \
26 				 driver))
27 
28 struct device platform_bus = {
29 	.init_name	= "platform",
30 };
31 EXPORT_SYMBOL_GPL(platform_bus);
32 
33 /**
34  * platform_get_resource - get a resource for a device
35  * @dev: platform device
36  * @type: resource type
37  * @num: resource index
38  */
39 struct resource *platform_get_resource(struct platform_device *dev,
40 				       unsigned int type, unsigned int num)
41 {
42 	int i;
43 
44 	for (i = 0; i < dev->num_resources; i++) {
45 		struct resource *r = &dev->resource[i];
46 
47 		if (type == resource_type(r) && num-- == 0)
48 			return r;
49 	}
50 	return NULL;
51 }
52 EXPORT_SYMBOL_GPL(platform_get_resource);
53 
54 /**
55  * platform_get_irq - get an IRQ for a device
56  * @dev: platform device
57  * @num: IRQ number index
58  */
59 int platform_get_irq(struct platform_device *dev, unsigned int num)
60 {
61 	struct resource *r = platform_get_resource(dev, IORESOURCE_IRQ, num);
62 
63 	return r ? r->start : -ENXIO;
64 }
65 EXPORT_SYMBOL_GPL(platform_get_irq);
66 
67 /**
68  * platform_get_resource_byname - get a resource for a device by name
69  * @dev: platform device
70  * @type: resource type
71  * @name: resource name
72  */
73 struct resource *platform_get_resource_byname(struct platform_device *dev,
74 					      unsigned int type,
75 					      const char *name)
76 {
77 	int i;
78 
79 	for (i = 0; i < dev->num_resources; i++) {
80 		struct resource *r = &dev->resource[i];
81 
82 		if (type == resource_type(r) && !strcmp(r->name, name))
83 			return r;
84 	}
85 	return NULL;
86 }
87 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
88 
89 /**
90  * platform_get_irq - get an IRQ for a device
91  * @dev: platform device
92  * @name: IRQ name
93  */
94 int platform_get_irq_byname(struct platform_device *dev, const char *name)
95 {
96 	struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ,
97 							  name);
98 
99 	return r ? r->start : -ENXIO;
100 }
101 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
102 
103 /**
104  * platform_add_devices - add a numbers of platform devices
105  * @devs: array of platform devices to add
106  * @num: number of platform devices in array
107  */
108 int platform_add_devices(struct platform_device **devs, int num)
109 {
110 	int i, ret = 0;
111 
112 	for (i = 0; i < num; i++) {
113 		ret = platform_device_register(devs[i]);
114 		if (ret) {
115 			while (--i >= 0)
116 				platform_device_unregister(devs[i]);
117 			break;
118 		}
119 	}
120 
121 	return ret;
122 }
123 EXPORT_SYMBOL_GPL(platform_add_devices);
124 
125 struct platform_object {
126 	struct platform_device pdev;
127 	char name[1];
128 };
129 
130 /**
131  * platform_device_put - destroy a platform device
132  * @pdev: platform device to free
133  *
134  * Free all memory associated with a platform device.  This function must
135  * _only_ be externally called in error cases.  All other usage is a bug.
136  */
137 void platform_device_put(struct platform_device *pdev)
138 {
139 	if (pdev)
140 		put_device(&pdev->dev);
141 }
142 EXPORT_SYMBOL_GPL(platform_device_put);
143 
144 static void platform_device_release(struct device *dev)
145 {
146 	struct platform_object *pa = container_of(dev, struct platform_object,
147 						  pdev.dev);
148 
149 	kfree(pa->pdev.dev.platform_data);
150 	kfree(pa->pdev.resource);
151 	kfree(pa);
152 }
153 
154 /**
155  * platform_device_alloc - create a platform device
156  * @name: base name of the device we're adding
157  * @id: instance id
158  *
159  * Create a platform device object which can have other objects attached
160  * to it, and which will have attached objects freed when it is released.
161  */
162 struct platform_device *platform_device_alloc(const char *name, int id)
163 {
164 	struct platform_object *pa;
165 
166 	pa = kzalloc(sizeof(struct platform_object) + strlen(name), GFP_KERNEL);
167 	if (pa) {
168 		strcpy(pa->name, name);
169 		pa->pdev.name = pa->name;
170 		pa->pdev.id = id;
171 		device_initialize(&pa->pdev.dev);
172 		pa->pdev.dev.release = platform_device_release;
173 	}
174 
175 	return pa ? &pa->pdev : NULL;
176 }
177 EXPORT_SYMBOL_GPL(platform_device_alloc);
178 
179 /**
180  * platform_device_add_resources - add resources to a platform device
181  * @pdev: platform device allocated by platform_device_alloc to add resources to
182  * @res: set of resources that needs to be allocated for the device
183  * @num: number of resources
184  *
185  * Add a copy of the resources to the platform device.  The memory
186  * associated with the resources will be freed when the platform device is
187  * released.
188  */
189 int platform_device_add_resources(struct platform_device *pdev,
190 				  const struct resource *res, unsigned int num)
191 {
192 	struct resource *r;
193 
194 	r = kmalloc(sizeof(struct resource) * num, GFP_KERNEL);
195 	if (r) {
196 		memcpy(r, res, sizeof(struct resource) * num);
197 		pdev->resource = r;
198 		pdev->num_resources = num;
199 	}
200 	return r ? 0 : -ENOMEM;
201 }
202 EXPORT_SYMBOL_GPL(platform_device_add_resources);
203 
204 /**
205  * platform_device_add_data - add platform-specific data to a platform device
206  * @pdev: platform device allocated by platform_device_alloc to add resources to
207  * @data: platform specific data for this platform device
208  * @size: size of platform specific data
209  *
210  * Add a copy of platform specific data to the platform device's
211  * platform_data pointer.  The memory associated with the platform data
212  * will be freed when the platform device is released.
213  */
214 int platform_device_add_data(struct platform_device *pdev, const void *data,
215 			     size_t size)
216 {
217 	void *d = kmemdup(data, size, GFP_KERNEL);
218 
219 	if (d) {
220 		pdev->dev.platform_data = d;
221 		return 0;
222 	}
223 	return -ENOMEM;
224 }
225 EXPORT_SYMBOL_GPL(platform_device_add_data);
226 
227 /**
228  * platform_device_add - add a platform device to device hierarchy
229  * @pdev: platform device we're adding
230  *
231  * This is part 2 of platform_device_register(), though may be called
232  * separately _iff_ pdev was allocated by platform_device_alloc().
233  */
234 int platform_device_add(struct platform_device *pdev)
235 {
236 	int i, ret = 0;
237 
238 	if (!pdev)
239 		return -EINVAL;
240 
241 	if (!pdev->dev.parent)
242 		pdev->dev.parent = &platform_bus;
243 
244 	pdev->dev.bus = &platform_bus_type;
245 
246 	if (pdev->id != -1)
247 		dev_set_name(&pdev->dev, "%s.%d", pdev->name,  pdev->id);
248 	else
249 		dev_set_name(&pdev->dev, "%s", pdev->name);
250 
251 	for (i = 0; i < pdev->num_resources; i++) {
252 		struct resource *p, *r = &pdev->resource[i];
253 
254 		if (r->name == NULL)
255 			r->name = dev_name(&pdev->dev);
256 
257 		p = r->parent;
258 		if (!p) {
259 			if (resource_type(r) == IORESOURCE_MEM)
260 				p = &iomem_resource;
261 			else if (resource_type(r) == IORESOURCE_IO)
262 				p = &ioport_resource;
263 		}
264 
265 		if (p && insert_resource(p, r)) {
266 			printk(KERN_ERR
267 			       "%s: failed to claim resource %d\n",
268 			       dev_name(&pdev->dev), i);
269 			ret = -EBUSY;
270 			goto failed;
271 		}
272 	}
273 
274 	pr_debug("Registering platform device '%s'. Parent at %s\n",
275 		 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
276 
277 	ret = device_add(&pdev->dev);
278 	if (ret == 0)
279 		return ret;
280 
281  failed:
282 	while (--i >= 0) {
283 		struct resource *r = &pdev->resource[i];
284 		unsigned long type = resource_type(r);
285 
286 		if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
287 			release_resource(r);
288 	}
289 
290 	return ret;
291 }
292 EXPORT_SYMBOL_GPL(platform_device_add);
293 
294 /**
295  * platform_device_del - remove a platform-level device
296  * @pdev: platform device we're removing
297  *
298  * Note that this function will also release all memory- and port-based
299  * resources owned by the device (@dev->resource).  This function must
300  * _only_ be externally called in error cases.  All other usage is a bug.
301  */
302 void platform_device_del(struct platform_device *pdev)
303 {
304 	int i;
305 
306 	if (pdev) {
307 		device_del(&pdev->dev);
308 
309 		for (i = 0; i < pdev->num_resources; i++) {
310 			struct resource *r = &pdev->resource[i];
311 			unsigned long type = resource_type(r);
312 
313 			if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
314 				release_resource(r);
315 		}
316 	}
317 }
318 EXPORT_SYMBOL_GPL(platform_device_del);
319 
320 /**
321  * platform_device_register - add a platform-level device
322  * @pdev: platform device we're adding
323  */
324 int platform_device_register(struct platform_device *pdev)
325 {
326 	device_initialize(&pdev->dev);
327 	return platform_device_add(pdev);
328 }
329 EXPORT_SYMBOL_GPL(platform_device_register);
330 
331 /**
332  * platform_device_unregister - unregister a platform-level device
333  * @pdev: platform device we're unregistering
334  *
335  * Unregistration is done in 2 steps. First we release all resources
336  * and remove it from the subsystem, then we drop reference count by
337  * calling platform_device_put().
338  */
339 void platform_device_unregister(struct platform_device *pdev)
340 {
341 	platform_device_del(pdev);
342 	platform_device_put(pdev);
343 }
344 EXPORT_SYMBOL_GPL(platform_device_unregister);
345 
346 /**
347  * platform_device_register_simple - add a platform-level device and its resources
348  * @name: base name of the device we're adding
349  * @id: instance id
350  * @res: set of resources that needs to be allocated for the device
351  * @num: number of resources
352  *
353  * This function creates a simple platform device that requires minimal
354  * resource and memory management. Canned release function freeing memory
355  * allocated for the device allows drivers using such devices to be
356  * unloaded without waiting for the last reference to the device to be
357  * dropped.
358  *
359  * This interface is primarily intended for use with legacy drivers which
360  * probe hardware directly.  Because such drivers create sysfs device nodes
361  * themselves, rather than letting system infrastructure handle such device
362  * enumeration tasks, they don't fully conform to the Linux driver model.
363  * In particular, when such drivers are built as modules, they can't be
364  * "hotplugged".
365  *
366  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
367  */
368 struct platform_device *platform_device_register_simple(const char *name,
369 							int id,
370 							const struct resource *res,
371 							unsigned int num)
372 {
373 	struct platform_device *pdev;
374 	int retval;
375 
376 	pdev = platform_device_alloc(name, id);
377 	if (!pdev) {
378 		retval = -ENOMEM;
379 		goto error;
380 	}
381 
382 	if (num) {
383 		retval = platform_device_add_resources(pdev, res, num);
384 		if (retval)
385 			goto error;
386 	}
387 
388 	retval = platform_device_add(pdev);
389 	if (retval)
390 		goto error;
391 
392 	return pdev;
393 
394 error:
395 	platform_device_put(pdev);
396 	return ERR_PTR(retval);
397 }
398 EXPORT_SYMBOL_GPL(platform_device_register_simple);
399 
400 /**
401  * platform_device_register_data - add a platform-level device with platform-specific data
402  * @parent: parent device for the device we're adding
403  * @name: base name of the device we're adding
404  * @id: instance id
405  * @data: platform specific data for this platform device
406  * @size: size of platform specific data
407  *
408  * This function creates a simple platform device that requires minimal
409  * resource and memory management. Canned release function freeing memory
410  * allocated for the device allows drivers using such devices to be
411  * unloaded without waiting for the last reference to the device to be
412  * dropped.
413  *
414  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
415  */
416 struct platform_device *platform_device_register_data(
417 		struct device *parent,
418 		const char *name, int id,
419 		const void *data, size_t size)
420 {
421 	struct platform_device *pdev;
422 	int retval;
423 
424 	pdev = platform_device_alloc(name, id);
425 	if (!pdev) {
426 		retval = -ENOMEM;
427 		goto error;
428 	}
429 
430 	pdev->dev.parent = parent;
431 
432 	if (size) {
433 		retval = platform_device_add_data(pdev, data, size);
434 		if (retval)
435 			goto error;
436 	}
437 
438 	retval = platform_device_add(pdev);
439 	if (retval)
440 		goto error;
441 
442 	return pdev;
443 
444 error:
445 	platform_device_put(pdev);
446 	return ERR_PTR(retval);
447 }
448 EXPORT_SYMBOL_GPL(platform_device_register_data);
449 
450 static int platform_drv_probe(struct device *_dev)
451 {
452 	struct platform_driver *drv = to_platform_driver(_dev->driver);
453 	struct platform_device *dev = to_platform_device(_dev);
454 
455 	return drv->probe(dev);
456 }
457 
458 static int platform_drv_probe_fail(struct device *_dev)
459 {
460 	return -ENXIO;
461 }
462 
463 static int platform_drv_remove(struct device *_dev)
464 {
465 	struct platform_driver *drv = to_platform_driver(_dev->driver);
466 	struct platform_device *dev = to_platform_device(_dev);
467 
468 	return drv->remove(dev);
469 }
470 
471 static void platform_drv_shutdown(struct device *_dev)
472 {
473 	struct platform_driver *drv = to_platform_driver(_dev->driver);
474 	struct platform_device *dev = to_platform_device(_dev);
475 
476 	drv->shutdown(dev);
477 }
478 
479 /**
480  * platform_driver_register - register a driver for platform-level devices
481  * @drv: platform driver structure
482  */
483 int platform_driver_register(struct platform_driver *drv)
484 {
485 	drv->driver.bus = &platform_bus_type;
486 	if (drv->probe)
487 		drv->driver.probe = platform_drv_probe;
488 	if (drv->remove)
489 		drv->driver.remove = platform_drv_remove;
490 	if (drv->shutdown)
491 		drv->driver.shutdown = platform_drv_shutdown;
492 
493 	return driver_register(&drv->driver);
494 }
495 EXPORT_SYMBOL_GPL(platform_driver_register);
496 
497 /**
498  * platform_driver_unregister - unregister a driver for platform-level devices
499  * @drv: platform driver structure
500  */
501 void platform_driver_unregister(struct platform_driver *drv)
502 {
503 	driver_unregister(&drv->driver);
504 }
505 EXPORT_SYMBOL_GPL(platform_driver_unregister);
506 
507 /**
508  * platform_driver_probe - register driver for non-hotpluggable device
509  * @drv: platform driver structure
510  * @probe: the driver probe routine, probably from an __init section
511  *
512  * Use this instead of platform_driver_register() when you know the device
513  * is not hotpluggable and has already been registered, and you want to
514  * remove its run-once probe() infrastructure from memory after the driver
515  * has bound to the device.
516  *
517  * One typical use for this would be with drivers for controllers integrated
518  * into system-on-chip processors, where the controller devices have been
519  * configured as part of board setup.
520  *
521  * Returns zero if the driver registered and bound to a device, else returns
522  * a negative error code and with the driver not registered.
523  */
524 int __init_or_module platform_driver_probe(struct platform_driver *drv,
525 		int (*probe)(struct platform_device *))
526 {
527 	int retval, code;
528 
529 	/* make sure driver won't have bind/unbind attributes */
530 	drv->driver.suppress_bind_attrs = true;
531 
532 	/* temporary section violation during probe() */
533 	drv->probe = probe;
534 	retval = code = platform_driver_register(drv);
535 
536 	/*
537 	 * Fixup that section violation, being paranoid about code scanning
538 	 * the list of drivers in order to probe new devices.  Check to see
539 	 * if the probe was successful, and make sure any forced probes of
540 	 * new devices fail.
541 	 */
542 	spin_lock(&platform_bus_type.p->klist_drivers.k_lock);
543 	drv->probe = NULL;
544 	if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
545 		retval = -ENODEV;
546 	drv->driver.probe = platform_drv_probe_fail;
547 	spin_unlock(&platform_bus_type.p->klist_drivers.k_lock);
548 
549 	if (code != retval)
550 		platform_driver_unregister(drv);
551 	return retval;
552 }
553 EXPORT_SYMBOL_GPL(platform_driver_probe);
554 
555 /**
556  * platform_create_bundle - register driver and create corresponding device
557  * @driver: platform driver structure
558  * @probe: the driver probe routine, probably from an __init section
559  * @res: set of resources that needs to be allocated for the device
560  * @n_res: number of resources
561  * @data: platform specific data for this platform device
562  * @size: size of platform specific data
563  *
564  * Use this in legacy-style modules that probe hardware directly and
565  * register a single platform device and corresponding platform driver.
566  *
567  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
568  */
569 struct platform_device * __init_or_module platform_create_bundle(
570 			struct platform_driver *driver,
571 			int (*probe)(struct platform_device *),
572 			struct resource *res, unsigned int n_res,
573 			const void *data, size_t size)
574 {
575 	struct platform_device *pdev;
576 	int error;
577 
578 	pdev = platform_device_alloc(driver->driver.name, -1);
579 	if (!pdev) {
580 		error = -ENOMEM;
581 		goto err_out;
582 	}
583 
584 	if (res) {
585 		error = platform_device_add_resources(pdev, res, n_res);
586 		if (error)
587 			goto err_pdev_put;
588 	}
589 
590 	if (data) {
591 		error = platform_device_add_data(pdev, data, size);
592 		if (error)
593 			goto err_pdev_put;
594 	}
595 
596 	error = platform_device_add(pdev);
597 	if (error)
598 		goto err_pdev_put;
599 
600 	error = platform_driver_probe(driver, probe);
601 	if (error)
602 		goto err_pdev_del;
603 
604 	return pdev;
605 
606 err_pdev_del:
607 	platform_device_del(pdev);
608 err_pdev_put:
609 	platform_device_put(pdev);
610 err_out:
611 	return ERR_PTR(error);
612 }
613 EXPORT_SYMBOL_GPL(platform_create_bundle);
614 
615 /* modalias support enables more hands-off userspace setup:
616  * (a) environment variable lets new-style hotplug events work once system is
617  *     fully running:  "modprobe $MODALIAS"
618  * (b) sysfs attribute lets new-style coldplug recover from hotplug events
619  *     mishandled before system is fully running:  "modprobe $(cat modalias)"
620  */
621 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
622 			     char *buf)
623 {
624 	struct platform_device	*pdev = to_platform_device(dev);
625 	int len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
626 
627 	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
628 }
629 
630 static struct device_attribute platform_dev_attrs[] = {
631 	__ATTR_RO(modalias),
632 	__ATTR_NULL,
633 };
634 
635 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
636 {
637 	struct platform_device	*pdev = to_platform_device(dev);
638 
639 	add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
640 		(pdev->id_entry) ? pdev->id_entry->name : pdev->name);
641 	return 0;
642 }
643 
644 static const struct platform_device_id *platform_match_id(
645 			const struct platform_device_id *id,
646 			struct platform_device *pdev)
647 {
648 	while (id->name[0]) {
649 		if (strcmp(pdev->name, id->name) == 0) {
650 			pdev->id_entry = id;
651 			return id;
652 		}
653 		id++;
654 	}
655 	return NULL;
656 }
657 
658 /**
659  * platform_match - bind platform device to platform driver.
660  * @dev: device.
661  * @drv: driver.
662  *
663  * Platform device IDs are assumed to be encoded like this:
664  * "<name><instance>", where <name> is a short description of the type of
665  * device, like "pci" or "floppy", and <instance> is the enumerated
666  * instance of the device, like '0' or '42'.  Driver IDs are simply
667  * "<name>".  So, extract the <name> from the platform_device structure,
668  * and compare it against the name of the driver. Return whether they match
669  * or not.
670  */
671 static int platform_match(struct device *dev, struct device_driver *drv)
672 {
673 	struct platform_device *pdev = to_platform_device(dev);
674 	struct platform_driver *pdrv = to_platform_driver(drv);
675 
676 	/* match against the id table first */
677 	if (pdrv->id_table)
678 		return platform_match_id(pdrv->id_table, pdev) != NULL;
679 
680 	/* fall-back to driver name match */
681 	return (strcmp(pdev->name, drv->name) == 0);
682 }
683 
684 #ifdef CONFIG_PM_SLEEP
685 
686 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
687 {
688 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
689 	struct platform_device *pdev = to_platform_device(dev);
690 	int ret = 0;
691 
692 	if (dev->driver && pdrv->suspend)
693 		ret = pdrv->suspend(pdev, mesg);
694 
695 	return ret;
696 }
697 
698 static int platform_legacy_resume(struct device *dev)
699 {
700 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
701 	struct platform_device *pdev = to_platform_device(dev);
702 	int ret = 0;
703 
704 	if (dev->driver && pdrv->resume)
705 		ret = pdrv->resume(pdev);
706 
707 	return ret;
708 }
709 
710 static int platform_pm_prepare(struct device *dev)
711 {
712 	struct device_driver *drv = dev->driver;
713 	int ret = 0;
714 
715 	if (drv && drv->pm && drv->pm->prepare)
716 		ret = drv->pm->prepare(dev);
717 
718 	return ret;
719 }
720 
721 static void platform_pm_complete(struct device *dev)
722 {
723 	struct device_driver *drv = dev->driver;
724 
725 	if (drv && drv->pm && drv->pm->complete)
726 		drv->pm->complete(dev);
727 }
728 
729 #else /* !CONFIG_PM_SLEEP */
730 
731 #define platform_pm_prepare		NULL
732 #define platform_pm_complete		NULL
733 
734 #endif /* !CONFIG_PM_SLEEP */
735 
736 #ifdef CONFIG_SUSPEND
737 
738 int __weak platform_pm_suspend(struct device *dev)
739 {
740 	struct device_driver *drv = dev->driver;
741 	int ret = 0;
742 
743 	if (!drv)
744 		return 0;
745 
746 	if (drv->pm) {
747 		if (drv->pm->suspend)
748 			ret = drv->pm->suspend(dev);
749 	} else {
750 		ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
751 	}
752 
753 	return ret;
754 }
755 
756 int __weak platform_pm_suspend_noirq(struct device *dev)
757 {
758 	struct device_driver *drv = dev->driver;
759 	int ret = 0;
760 
761 	if (!drv)
762 		return 0;
763 
764 	if (drv->pm) {
765 		if (drv->pm->suspend_noirq)
766 			ret = drv->pm->suspend_noirq(dev);
767 	}
768 
769 	return ret;
770 }
771 
772 int __weak platform_pm_resume(struct device *dev)
773 {
774 	struct device_driver *drv = dev->driver;
775 	int ret = 0;
776 
777 	if (!drv)
778 		return 0;
779 
780 	if (drv->pm) {
781 		if (drv->pm->resume)
782 			ret = drv->pm->resume(dev);
783 	} else {
784 		ret = platform_legacy_resume(dev);
785 	}
786 
787 	return ret;
788 }
789 
790 int __weak platform_pm_resume_noirq(struct device *dev)
791 {
792 	struct device_driver *drv = dev->driver;
793 	int ret = 0;
794 
795 	if (!drv)
796 		return 0;
797 
798 	if (drv->pm) {
799 		if (drv->pm->resume_noirq)
800 			ret = drv->pm->resume_noirq(dev);
801 	}
802 
803 	return ret;
804 }
805 
806 #else /* !CONFIG_SUSPEND */
807 
808 #define platform_pm_suspend		NULL
809 #define platform_pm_resume		NULL
810 #define platform_pm_suspend_noirq	NULL
811 #define platform_pm_resume_noirq	NULL
812 
813 #endif /* !CONFIG_SUSPEND */
814 
815 #ifdef CONFIG_HIBERNATION
816 
817 static int platform_pm_freeze(struct device *dev)
818 {
819 	struct device_driver *drv = dev->driver;
820 	int ret = 0;
821 
822 	if (!drv)
823 		return 0;
824 
825 	if (drv->pm) {
826 		if (drv->pm->freeze)
827 			ret = drv->pm->freeze(dev);
828 	} else {
829 		ret = platform_legacy_suspend(dev, PMSG_FREEZE);
830 	}
831 
832 	return ret;
833 }
834 
835 static int platform_pm_freeze_noirq(struct device *dev)
836 {
837 	struct device_driver *drv = dev->driver;
838 	int ret = 0;
839 
840 	if (!drv)
841 		return 0;
842 
843 	if (drv->pm) {
844 		if (drv->pm->freeze_noirq)
845 			ret = drv->pm->freeze_noirq(dev);
846 	}
847 
848 	return ret;
849 }
850 
851 static int platform_pm_thaw(struct device *dev)
852 {
853 	struct device_driver *drv = dev->driver;
854 	int ret = 0;
855 
856 	if (!drv)
857 		return 0;
858 
859 	if (drv->pm) {
860 		if (drv->pm->thaw)
861 			ret = drv->pm->thaw(dev);
862 	} else {
863 		ret = platform_legacy_resume(dev);
864 	}
865 
866 	return ret;
867 }
868 
869 static int platform_pm_thaw_noirq(struct device *dev)
870 {
871 	struct device_driver *drv = dev->driver;
872 	int ret = 0;
873 
874 	if (!drv)
875 		return 0;
876 
877 	if (drv->pm) {
878 		if (drv->pm->thaw_noirq)
879 			ret = drv->pm->thaw_noirq(dev);
880 	}
881 
882 	return ret;
883 }
884 
885 static int platform_pm_poweroff(struct device *dev)
886 {
887 	struct device_driver *drv = dev->driver;
888 	int ret = 0;
889 
890 	if (!drv)
891 		return 0;
892 
893 	if (drv->pm) {
894 		if (drv->pm->poweroff)
895 			ret = drv->pm->poweroff(dev);
896 	} else {
897 		ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
898 	}
899 
900 	return ret;
901 }
902 
903 static int platform_pm_poweroff_noirq(struct device *dev)
904 {
905 	struct device_driver *drv = dev->driver;
906 	int ret = 0;
907 
908 	if (!drv)
909 		return 0;
910 
911 	if (drv->pm) {
912 		if (drv->pm->poweroff_noirq)
913 			ret = drv->pm->poweroff_noirq(dev);
914 	}
915 
916 	return ret;
917 }
918 
919 static int platform_pm_restore(struct device *dev)
920 {
921 	struct device_driver *drv = dev->driver;
922 	int ret = 0;
923 
924 	if (!drv)
925 		return 0;
926 
927 	if (drv->pm) {
928 		if (drv->pm->restore)
929 			ret = drv->pm->restore(dev);
930 	} else {
931 		ret = platform_legacy_resume(dev);
932 	}
933 
934 	return ret;
935 }
936 
937 static int platform_pm_restore_noirq(struct device *dev)
938 {
939 	struct device_driver *drv = dev->driver;
940 	int ret = 0;
941 
942 	if (!drv)
943 		return 0;
944 
945 	if (drv->pm) {
946 		if (drv->pm->restore_noirq)
947 			ret = drv->pm->restore_noirq(dev);
948 	}
949 
950 	return ret;
951 }
952 
953 #else /* !CONFIG_HIBERNATION */
954 
955 #define platform_pm_freeze		NULL
956 #define platform_pm_thaw		NULL
957 #define platform_pm_poweroff		NULL
958 #define platform_pm_restore		NULL
959 #define platform_pm_freeze_noirq	NULL
960 #define platform_pm_thaw_noirq		NULL
961 #define platform_pm_poweroff_noirq	NULL
962 #define platform_pm_restore_noirq	NULL
963 
964 #endif /* !CONFIG_HIBERNATION */
965 
966 #ifdef CONFIG_PM_RUNTIME
967 
968 int __weak platform_pm_runtime_suspend(struct device *dev)
969 {
970 	return pm_generic_runtime_suspend(dev);
971 };
972 
973 int __weak platform_pm_runtime_resume(struct device *dev)
974 {
975 	return pm_generic_runtime_resume(dev);
976 };
977 
978 int __weak platform_pm_runtime_idle(struct device *dev)
979 {
980 	return pm_generic_runtime_idle(dev);
981 };
982 
983 #else /* !CONFIG_PM_RUNTIME */
984 
985 #define platform_pm_runtime_suspend NULL
986 #define platform_pm_runtime_resume NULL
987 #define platform_pm_runtime_idle NULL
988 
989 #endif /* !CONFIG_PM_RUNTIME */
990 
991 static const struct dev_pm_ops platform_dev_pm_ops = {
992 	.prepare = platform_pm_prepare,
993 	.complete = platform_pm_complete,
994 	.suspend = platform_pm_suspend,
995 	.resume = platform_pm_resume,
996 	.freeze = platform_pm_freeze,
997 	.thaw = platform_pm_thaw,
998 	.poweroff = platform_pm_poweroff,
999 	.restore = platform_pm_restore,
1000 	.suspend_noirq = platform_pm_suspend_noirq,
1001 	.resume_noirq = platform_pm_resume_noirq,
1002 	.freeze_noirq = platform_pm_freeze_noirq,
1003 	.thaw_noirq = platform_pm_thaw_noirq,
1004 	.poweroff_noirq = platform_pm_poweroff_noirq,
1005 	.restore_noirq = platform_pm_restore_noirq,
1006 	.runtime_suspend = platform_pm_runtime_suspend,
1007 	.runtime_resume = platform_pm_runtime_resume,
1008 	.runtime_idle = platform_pm_runtime_idle,
1009 };
1010 
1011 struct bus_type platform_bus_type = {
1012 	.name		= "platform",
1013 	.dev_attrs	= platform_dev_attrs,
1014 	.match		= platform_match,
1015 	.uevent		= platform_uevent,
1016 	.pm		= &platform_dev_pm_ops,
1017 };
1018 EXPORT_SYMBOL_GPL(platform_bus_type);
1019 
1020 int __init platform_bus_init(void)
1021 {
1022 	int error;
1023 
1024 	early_platform_cleanup();
1025 
1026 	error = device_register(&platform_bus);
1027 	if (error)
1028 		return error;
1029 	error =  bus_register(&platform_bus_type);
1030 	if (error)
1031 		device_unregister(&platform_bus);
1032 	return error;
1033 }
1034 
1035 #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
1036 u64 dma_get_required_mask(struct device *dev)
1037 {
1038 	u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
1039 	u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
1040 	u64 mask;
1041 
1042 	if (!high_totalram) {
1043 		/* convert to mask just covering totalram */
1044 		low_totalram = (1 << (fls(low_totalram) - 1));
1045 		low_totalram += low_totalram - 1;
1046 		mask = low_totalram;
1047 	} else {
1048 		high_totalram = (1 << (fls(high_totalram) - 1));
1049 		high_totalram += high_totalram - 1;
1050 		mask = (((u64)high_totalram) << 32) + 0xffffffff;
1051 	}
1052 	return mask;
1053 }
1054 EXPORT_SYMBOL_GPL(dma_get_required_mask);
1055 #endif
1056 
1057 static __initdata LIST_HEAD(early_platform_driver_list);
1058 static __initdata LIST_HEAD(early_platform_device_list);
1059 
1060 /**
1061  * early_platform_driver_register - register early platform driver
1062  * @epdrv: early_platform driver structure
1063  * @buf: string passed from early_param()
1064  *
1065  * Helper function for early_platform_init() / early_platform_init_buffer()
1066  */
1067 int __init early_platform_driver_register(struct early_platform_driver *epdrv,
1068 					  char *buf)
1069 {
1070 	char *tmp;
1071 	int n;
1072 
1073 	/* Simply add the driver to the end of the global list.
1074 	 * Drivers will by default be put on the list in compiled-in order.
1075 	 */
1076 	if (!epdrv->list.next) {
1077 		INIT_LIST_HEAD(&epdrv->list);
1078 		list_add_tail(&epdrv->list, &early_platform_driver_list);
1079 	}
1080 
1081 	/* If the user has specified device then make sure the driver
1082 	 * gets prioritized. The driver of the last device specified on
1083 	 * command line will be put first on the list.
1084 	 */
1085 	n = strlen(epdrv->pdrv->driver.name);
1086 	if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
1087 		list_move(&epdrv->list, &early_platform_driver_list);
1088 
1089 		/* Allow passing parameters after device name */
1090 		if (buf[n] == '\0' || buf[n] == ',')
1091 			epdrv->requested_id = -1;
1092 		else {
1093 			epdrv->requested_id = simple_strtoul(&buf[n + 1],
1094 							     &tmp, 10);
1095 
1096 			if (buf[n] != '.' || (tmp == &buf[n + 1])) {
1097 				epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
1098 				n = 0;
1099 			} else
1100 				n += strcspn(&buf[n + 1], ",") + 1;
1101 		}
1102 
1103 		if (buf[n] == ',')
1104 			n++;
1105 
1106 		if (epdrv->bufsize) {
1107 			memcpy(epdrv->buffer, &buf[n],
1108 			       min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
1109 			epdrv->buffer[epdrv->bufsize - 1] = '\0';
1110 		}
1111 	}
1112 
1113 	return 0;
1114 }
1115 
1116 /**
1117  * early_platform_add_devices - adds a number of early platform devices
1118  * @devs: array of early platform devices to add
1119  * @num: number of early platform devices in array
1120  *
1121  * Used by early architecture code to register early platform devices and
1122  * their platform data.
1123  */
1124 void __init early_platform_add_devices(struct platform_device **devs, int num)
1125 {
1126 	struct device *dev;
1127 	int i;
1128 
1129 	/* simply add the devices to list */
1130 	for (i = 0; i < num; i++) {
1131 		dev = &devs[i]->dev;
1132 
1133 		if (!dev->devres_head.next) {
1134 			INIT_LIST_HEAD(&dev->devres_head);
1135 			list_add_tail(&dev->devres_head,
1136 				      &early_platform_device_list);
1137 		}
1138 	}
1139 }
1140 
1141 /**
1142  * early_platform_driver_register_all - register early platform drivers
1143  * @class_str: string to identify early platform driver class
1144  *
1145  * Used by architecture code to register all early platform drivers
1146  * for a certain class. If omitted then only early platform drivers
1147  * with matching kernel command line class parameters will be registered.
1148  */
1149 void __init early_platform_driver_register_all(char *class_str)
1150 {
1151 	/* The "class_str" parameter may or may not be present on the kernel
1152 	 * command line. If it is present then there may be more than one
1153 	 * matching parameter.
1154 	 *
1155 	 * Since we register our early platform drivers using early_param()
1156 	 * we need to make sure that they also get registered in the case
1157 	 * when the parameter is missing from the kernel command line.
1158 	 *
1159 	 * We use parse_early_options() to make sure the early_param() gets
1160 	 * called at least once. The early_param() may be called more than
1161 	 * once since the name of the preferred device may be specified on
1162 	 * the kernel command line. early_platform_driver_register() handles
1163 	 * this case for us.
1164 	 */
1165 	parse_early_options(class_str);
1166 }
1167 
1168 /**
1169  * early_platform_match - find early platform device matching driver
1170  * @epdrv: early platform driver structure
1171  * @id: id to match against
1172  */
1173 static  __init struct platform_device *
1174 early_platform_match(struct early_platform_driver *epdrv, int id)
1175 {
1176 	struct platform_device *pd;
1177 
1178 	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1179 		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1180 			if (pd->id == id)
1181 				return pd;
1182 
1183 	return NULL;
1184 }
1185 
1186 /**
1187  * early_platform_left - check if early platform driver has matching devices
1188  * @epdrv: early platform driver structure
1189  * @id: return true if id or above exists
1190  */
1191 static  __init int early_platform_left(struct early_platform_driver *epdrv,
1192 				       int id)
1193 {
1194 	struct platform_device *pd;
1195 
1196 	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1197 		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1198 			if (pd->id >= id)
1199 				return 1;
1200 
1201 	return 0;
1202 }
1203 
1204 /**
1205  * early_platform_driver_probe_id - probe drivers matching class_str and id
1206  * @class_str: string to identify early platform driver class
1207  * @id: id to match against
1208  * @nr_probe: number of platform devices to successfully probe before exiting
1209  */
1210 static int __init early_platform_driver_probe_id(char *class_str,
1211 						 int id,
1212 						 int nr_probe)
1213 {
1214 	struct early_platform_driver *epdrv;
1215 	struct platform_device *match;
1216 	int match_id;
1217 	int n = 0;
1218 	int left = 0;
1219 
1220 	list_for_each_entry(epdrv, &early_platform_driver_list, list) {
1221 		/* only use drivers matching our class_str */
1222 		if (strcmp(class_str, epdrv->class_str))
1223 			continue;
1224 
1225 		if (id == -2) {
1226 			match_id = epdrv->requested_id;
1227 			left = 1;
1228 
1229 		} else {
1230 			match_id = id;
1231 			left += early_platform_left(epdrv, id);
1232 
1233 			/* skip requested id */
1234 			switch (epdrv->requested_id) {
1235 			case EARLY_PLATFORM_ID_ERROR:
1236 			case EARLY_PLATFORM_ID_UNSET:
1237 				break;
1238 			default:
1239 				if (epdrv->requested_id == id)
1240 					match_id = EARLY_PLATFORM_ID_UNSET;
1241 			}
1242 		}
1243 
1244 		switch (match_id) {
1245 		case EARLY_PLATFORM_ID_ERROR:
1246 			pr_warning("%s: unable to parse %s parameter\n",
1247 				   class_str, epdrv->pdrv->driver.name);
1248 			/* fall-through */
1249 		case EARLY_PLATFORM_ID_UNSET:
1250 			match = NULL;
1251 			break;
1252 		default:
1253 			match = early_platform_match(epdrv, match_id);
1254 		}
1255 
1256 		if (match) {
1257 			/*
1258 			 * Set up a sensible init_name to enable
1259 			 * dev_name() and others to be used before the
1260 			 * rest of the driver core is initialized.
1261 			 */
1262 			if (!match->dev.init_name && slab_is_available()) {
1263 				if (match->id != -1)
1264 					match->dev.init_name =
1265 						kasprintf(GFP_KERNEL, "%s.%d",
1266 							  match->name,
1267 							  match->id);
1268 				else
1269 					match->dev.init_name =
1270 						kasprintf(GFP_KERNEL, "%s",
1271 							  match->name);
1272 
1273 				if (!match->dev.init_name)
1274 					return -ENOMEM;
1275 			}
1276 
1277 			if (epdrv->pdrv->probe(match))
1278 				pr_warning("%s: unable to probe %s early.\n",
1279 					   class_str, match->name);
1280 			else
1281 				n++;
1282 		}
1283 
1284 		if (n >= nr_probe)
1285 			break;
1286 	}
1287 
1288 	if (left)
1289 		return n;
1290 	else
1291 		return -ENODEV;
1292 }
1293 
1294 /**
1295  * early_platform_driver_probe - probe a class of registered drivers
1296  * @class_str: string to identify early platform driver class
1297  * @nr_probe: number of platform devices to successfully probe before exiting
1298  * @user_only: only probe user specified early platform devices
1299  *
1300  * Used by architecture code to probe registered early platform drivers
1301  * within a certain class. For probe to happen a registered early platform
1302  * device matching a registered early platform driver is needed.
1303  */
1304 int __init early_platform_driver_probe(char *class_str,
1305 				       int nr_probe,
1306 				       int user_only)
1307 {
1308 	int k, n, i;
1309 
1310 	n = 0;
1311 	for (i = -2; n < nr_probe; i++) {
1312 		k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
1313 
1314 		if (k < 0)
1315 			break;
1316 
1317 		n += k;
1318 
1319 		if (user_only)
1320 			break;
1321 	}
1322 
1323 	return n;
1324 }
1325 
1326 /**
1327  * early_platform_cleanup - clean up early platform code
1328  */
1329 void __init early_platform_cleanup(void)
1330 {
1331 	struct platform_device *pd, *pd2;
1332 
1333 	/* clean up the devres list used to chain devices */
1334 	list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
1335 				 dev.devres_head) {
1336 		list_del(&pd->dev.devres_head);
1337 		memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));
1338 	}
1339 }
1340 
1341